factoriser en utilisant les produits remarquables

a = 4x²-20x+25
a =(2x+5)²

b = 9x²-1
b =(3x+1)(3x-1)

c =25x²+10x+1
c =(5x+1)²

d =x²-1/36
d = (x-1/6)(x+1/6)

e = x² -x +1/4
e =(x-1/2)²

f = x²/9 =100
x²/9-100
(x/3-10)(x/3+10)

g =x²-2/3x+1/9
g =(x-1/3)²

A = 4x²-20x+25
A =(2x+5)²

B= 9x²-1
B =(3x+1)(3x-1)

C =25x²+10x+1
C =(5x+1)²

D =x²-1/36
D = (x-1/6)(x+1/6)

E = x² -x +1/4
E =(x-1/2)²

F= x²/9 =100
F=x²/9-100
F=(x/3-10)(x/3+10)

G =x²-2/3x+1/9
G =(x-1/3)²